Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/26/2001
Publication Date: N/A
Citation: Interpretive Summary: In an earlier study we identified that the levels of a blood protein called ovotransferrin (OT) is increased in chickens with infections. We have developed a method to measure the levels of OT in the blood. Using this method we show that the levels of OT in blood of chickens with different bacterial and viral diseases is in fact, significantly increased compared to those birds that did not have the disease. We propose that the blood O levels can be used as an indicator of the presence of health problems in poultry.
Technical Abstract: Serum ovotransferrin (OTF) is an acute phase protein (APP) in chickens. We developed a competitive enzyme immunoassay (EIA) to measure the changes in serum levels of OTF during inflammation and infectious diseases in chickens. The assay is based on the competition of serum OTF with biotinylated OTF to bind to a rabbit anti-chicken transferrin antibody. Bound biotinylated OTF is then detected using streptavidin conjugated to horseradish peroxidase (SA-HRP). Serum levels of OTF are calculated according to a standard curve generated using known concentrations of OTF. In experimentally-induced inflammation, 4-wk-old male broiler chickens injected with croton oil had an increased serum level of OTF at 16 h post- injection, which reached a peak at 72 h, remained high through 120 h, and returned to the basal level of olive oil-injected controls by 240 h. There were no statistical changes in serum levels of OTF in olive oil-treated control birds at any time points. For studies with poultry diseases, specific pathogen free (SPF) chickens were challenged with known bacterial and viral pathogens and serum was collected at the height of the infection. Compared to untreated control birds, SPF chickens challenged with Escherichia coli (E. coli), fowlpox virus (FPV), respiratory enteric orphan virus (Reovirus), infectious bursal disease virus (IBDV), infectious bronchitis virus (IBV), or infectious laryngotracheitis virus (ILTV) had higher levels of OTF in serum. These results demonstrate that serum OTF can be used as a nonspecific clinical marker for inflammation associated with traumatic or infectious avian diseases.